Apparatus for forming helical plow screws



April 28, 1942. M. H. PITCHER 2,280,847

APPARATUS FOR FORMING HELI ICAL PLOW SCREWS Filed July 12, 1940 2 Shets-Sheet 1 uvMENrU r'uLEs H. PH'CHER En T April 28, 1942. M. H. PITCHER 2,280,347

APPARATUS FOR FORMING HELICAL PLOW SCREWS Filed July 12, 1940 2 Sheets-Sheet 2 ANA/EN 75R M\LE5 H. PITCHER ,4 7- TU NE Patented Apr. 28, 1942 2,280,847 APPARATUS roa roams HELICAL now soanws Miles 11. Pitcher, Portland, Oreg. Application July 12, 1940, Serial No. 345,128

3 Claims.

This invention relates generally to the manufacture of conveyor flights, and particularly to a method of and apparatus for forming helical plow screws.

The main object of this invention is to construct an apparatus and develop a method for easily forming helical screws especially adapted for use in rotary plows, such as are illustrated in the patent of Bagan, No. 1,776,612.

The second object is to construct a' machine of the class described whereby the radial curvature of the flight as well as the pitch thereof may be varied at will.

These and other objects are accomplished in. the manner set forth in the following specification as illustrated in the accompanying drawings, in which:

Fig. 1 is a horizontal section through the apparatus taken along the line in Fig. 2.

Fig. 2 is a front elevation of the device.

Fig. 3 is a plan of a representative form of blank made from sheet steel.

Fig. 4 is a side elevation showing a plurality of blanks welded together along their radial edges forming a helix having a small pitch and with the flight thereof unformed.

Fig. 5 is a fragmentary side elevation of a formed helical plow screw indicating the manner in which the helix shown in Fig. 4 appears after it has passed through my machine.

Fig. 6 is a fragmentary section taken along the line 5-5 in Fig. 1.

Fig. 7 is a fragmentary section taken along the line 1-1 in Fig. 1.

Fig. 8 is a fragmentary section taken along the line H in Fig. 2 showing the position of the rollers which engage the edges of the plow screw.

Fig. 9 is a fragmentary section taken along the line 55 in Fig. 1.

Similar numerals refer to similar parts throughout the several views.

Referring in detail to the drawings, there is shown a somewhat rectangular upright frame III having its side ll inclined with relation to the remaining sides. The frame I is provided with feet l2 by means of which the machine may be secured to a suitable foundation.

Through the side II is formed an opening l3 through which projects the fixed conical rolls l4 and I and the adjustable roll Ii. The lower roll I4 is mounted on a spindle H which journals in the bearings It and I! which are secured to the frame It. The spindle I! is connected by means of a universal joint 24 to the shaft 2| frame Ill. The shaft 2| is also supported by the bearing 23 which is mounted on the frame III. A gear 24 is secured to the shaft 2|.

The conical roll I5 is mounted on a spindle 25 which journals in the bearings-25 and 21, both of which are attached to the frame II. The spindle 25 is connected by the universal joint 28 to the shaft 29 which journals in the bearing 30 forming part of the frame I0, and the shaft 29 also journals in the bearing 3| which is attached to the frame Ill. On the shaft 29 is secured a gear 32.

The gears 24 and 32 mesh with an intermediate pinion 33 which is secured on the shaft 34 which journals in the bearings 35 and 35 and is driven from the pulley 3'! through a belt 38 from a convenient source of power. The adjacent faces 38 of the rolls I4 and I5 are substantially parallel and spaced from each other.

The adjustable roll I5 is mounted on a'spindie 40 which journals in a floating frame 4| and has its end 42 splined within the end 43 of the universal coupling 44 which is connected by means of the stub shaft 45 and the second universal coupling 45 to the shaft 41 which journals in the frame It. On the shaft 41 is secured a sprocket wheel 45 whose chain 49 passes around the sprocket wheel 50 secured to the shaft 29 and around the idler sprocket wheel 5| which is rotatably mounted on the bolt 52. An idler sprocket wheel 53 is employed under the upper run of the chain 49.

A flat spring 54 is securedto the stationary bracket 55 and the spring end 55 bears against the side 51 of the floating frame 4| and urges the roll l5 away from the rolls l4 and I5 against the slidable stop 58 which is adjustably held by means of the screw 59 which is threaded through the frame lug 60 and locked in position by means of the nut 5|. Suitable thrust bearings 52 are provided for the various spindles ll, 25, and 40.

In Fig. 9 is shown a pair of guides 63 between which is mounted a slide 54 whose position may be adjusted by means of the screw 55. The slide 64 has pivotally mounted therein the end 56 of the floating frame 4|. The trunnions 51 of the end 55 journal in openings 58 formed within the slide 54.

It can be seen that by rotating the screws 59 and 55 that the angular as well as the spaced relationship between the spindle 40 and the spindles l1 and 25 may be varied at will and that this relationship may be easily fixed.

It will be noted in Fig. 8 that there is shown a which journals in the bearing 22 formed in the 55 roller 69 which guides against the outer edge Ill tion thereto by the nuts II. There is also shown a roller 15 which is carried by the head 16 of the adjusting screw 11 which passes through the frame l and is held in relation thereto by means or the nuts 18. The roller 15 engages the outer edge I0 0! the plow screw II.

There is shown in Figs. 1 and 2 a trough 80 which is adjustably supported on the bracket 81. The trough 80 is of a nature to support the blanks 82 which have been slit along the line 83 and welded together into helical form as shown mm. 4.

The operation of the device is as follows:

The joined blanks 82 will be referred to as the untormed screw 84 which is placed in the trough 80 and the end 85 is passed downwardly between the rolls l4, l5 and I6 causing the formation of the helix II, that is the plow screw shown in Fig. 5. The spacing of the rolls l4, I6 and I6 and the relation of the rollers 69 and I5 is such that a screw of extremely accurate form is produced and also that there is a slight radial curvature to the flight of the helix which is essential for plowing purposes.

It is obvious that the diameters of the screw H across the outer edge 1.0 as well as the inner edge 10 is less than the corresponding diameters of the blanks 82.

I claim:

1. An apparatus of the class described having in combination three tapering driven rolls, the axes of which converge normally toward a'common point, the axes of two of said rolls being fixed while the axis of the third roll is adjustable in a plane normal to and intersecting a plane passing through the axes of said fixed rolls and guide rolls associated with said adjustable taperin'g roll constituting guides for work passing between said tapering rolls for the purpose of controlling the angular position of the work as it passes between said tapering rolls.

2. In an apparatus of the class described, the combination of a frame, a pair of converging tapering rolls rotatably mounted on said frame on fixed axes, a third tapering roll adjustable with relation to said first mentioned rolls as to spacing and angularity, said adjustment being in a plane substantially normal to a plane passing through the axes of said fixed rolls, means for driving all of said rolls simultaneously, means for adjusting said adjustable roll, and means for controlling the angle at which work is passed between said rolls.

3. The apparatus described in claim 2, together with a spring for urging said adjustable roll away from said fixed rolls.

NIILES H. PITCHER. 

